Fifteen male and 9 female patients between 14 and 41 years of age who suffered from acne were included in this study. Sixteen endocrine normal males and 27 females were used as controls. Skin and venous blood samples were taken from both normal and acne patients. Specific estrogen and androgen receptor levels were assayed under conditions resulting in the estimation of unoccupied receptor levels, and the charcoal technique was utilized. Testosterone serum levels were determined by radioimmunoassay. No estrogen receptors could be found in the normal skin. Of the male and female acne patients 93 and 78%, respectively, were estrogen receptor-positive, and their levels were between 11 and 275 fmol/mg cytosol protein. On the other hand, 31 and 48%, respectively, of the male and female acne patients were androgen receptor-positive, and their receptor levels were between 35 and 213 fmol/mg cytosol protein. A correlation of r = 0.71 between estrogen and androgen receptor levels was noted in the female subjects, but no correlation was found in the male subjects. A correlation between testosterone serum levels and androgen receptor levels of r = 0.77 and r = 0.66, respectively, was noted in the female and male acne patients. The results of the present investigation suggest that androgen receptor levels play an important role in acne patients with normal testosterone serum levels. In addition, the presence of estrogen receptor levels in acne patients indicates a possible therapy by anti-estrogens or estrogens.